My invention pertains to an automatic control system for a railroad interlocking. More specifically, the invention pertains to an automatic control system for alternating the movement of trains from two converging tracks into a single track stretch.
Frequently in rapid transit operation, trains from two branch line tracks converge into a single track stretch as they approach and enter a station area. Such trains approach under automatic signal control in the usual rapid transit system. In other words, these trains continue their forward movement along the branch lines in accordance with wayside signal indications which reflect advance traffic conditions and thus are not directly under the remote control of a system operator who therefore need not concern himself with the specific control of such approaching trains. The duties of the system operator can be further reduced if automatic control can be provided to position the switch at the junction point of the converging branch lines leading into the station area. The approaching trains then initiate a switch position control and the clearing of the station entering signal without requiring any specific, manual operations by the system operator. However, to maintain proper scheduling, it is frequently desirable to alternate trains from each branch line into the station. This creates no problem if sufficient headway exists to assure that only one train at a time approaches the junction switch location. Normally during rush hours, both approach tracks may be continuously occupied so that, unless special control provisions are provided, one route may hold in an established position to clear all trains from that branch line in succession. Therefore to meet the schedule and/or the operational requirements, the interlocking routes must be controlled to authorize approaching trains to enter the station alternately from the branch lines.
Accordingly, an object of my invention is an improved automatic interlocking control system for converging trains.
Another object of the invention is a control system for automatically alternating the movement of successive trains from two converging tracks over a junction switch into a single track stretch.
A further object of the invention is a system for automatically authorizing the alternate entry of trains from two branch tracks into a single track.
Still another object of my invention is a circuit arrangement which automatically clears alternate routes from two converging branch line tracks to a single track for trains successively approaching on both branch tracks.
It is also an object of my invention to provide an automatic interlocking control system for the junction switch of two converging tracks which alternately establishes routes from each track for trains successively approaching the junction location.
Other objects, features, and advantages of my invention will become apparent from the following specification when taken in connection with the accompanying drawing and appended claims.